An automatic transmission and the like mounted on a vehicle is provided with a parking device that allows the vehicle to be in a parking state by regulating a rotation of an output shaft that transmits a rotation to a drive wheel or a rotation of an intermediate shaft configured to be able to transmit a rotation to the output shaft (Patent Document 1, for example).
The parking device in Patent Document 1 includes a parking gear that is integrally provided with the output shaft of the automatic transmission, a parking pawl having a tab that is engaged with a tooth space of the parking gear, a support disposed in proximity to the lower part of the parking pawl, a cam that oscillates the parking pawl vertically by being inserted and removed between the parking pawl and the support, a parking rod to which the cam is fitted by insertion, a rotational lever connected to one end of the parking rod which is opposite from the other end to which the cam is fitted by insertion, a torsion coil spring provided on the rotation shaft of the rotational lever, and a hydraulic piston of which the end is in contact with the rotational lever. The torsion coil spring urges the rotational lever so as to press the parking rod toward the parking gear, whereby the vehicle is in the parking state. With this urging force, the parking state is maintained. Due to the force from the hydraulic piston acting on the rotational lever, the rotational lever is rotated so as to pull the parking rod from the parking gear side while resisting to the urging force of the torsion coil spring, and the parking state is released.